I'm trying to make a combobox in ASP.NET MVC 3.0 where the user can either type in a value in a text field or select a value from a drop down. The user should not be restricted to the values in the select list. The view has a viewmodel, so the values need to be populated and posted to the controller action through model binding.
I've created a decent jquery solution based on the jquery autocomplete widget, but I haven't got it to play well with the MVC unobtrusive javascript validation. I'm making progress with this HtmlHelper extension, but I'm wrestling with UI issues with IE/compatibility mode and my existing CSS. Paying for a control suite like Telerik or Infragistics is not possible. (EDIT: This is a commercial app, so I can't use the free Telerik controls because they are GPL and if you use a GPL component in your app, your entire app becomes GPL).
Does anyone have a great ComboBox for MVC?